Question 1

Which one of the following statements about Pax6 and eye development is INCORRECT?

Accepted Answer

A) Binding of Pax6 protein to the cis-regulatory elements of its target genes results in activation of some genes and repression of others. 
B) The specific program of eye development for a given species depends on the genes downstream of Pax6 in that species' genome. 
C) In the fruit fly, the total number of genes downstream of Pax6 that are needed for eye development is approximately 2000. 
D) Some of the genes influenced by Pax6 protein are activated or repressed indirectly by other transcription factors "turned on" by Pax6. 
E) The downstream target genes for Pax6 protein in different organisms are all very similar. 
A) Binding of Pax6 protein to the cis-regulatory elements of its target genes results in activation of some genes and repression of others. 
B) The specific program of eye development for a given species depends on the genes downstream of Pax6 in that species' genome. 
C) In the fruit fly, the total number of genes downstream of Pax6 that are needed for eye development is approximately 2000. 
D) Some of the genes influenced by Pax6 protein are activated or repressed indirectly by other transcription factors "turned on" by Pax6. 
E) The downstream target genes for Pax6 protein in different organisms are all very similar.

Question 2

In animals, homeotic genes:

Accepted Answer

A) encode transcription factors. 
B) specify the identities of individual body parts or segments during development. 
C) are controlled by segment-polarity genes expressed earlier in development. 
D) are found in a wide variety of animals with bilateral symmetry, from fruit flies to vertebrates. 
E) All of these choices are correct. 
A) encode transcription factors. 
B) specify the identities of individual body parts or segments during development. 
C) are controlled by segment-polarity genes expressed earlier in development. 
D) are found in a wide variety of animals with bilateral symmetry, from fruit flies to vertebrates. 
E) All of these choices are correct.

Question 3

In the roundworm Caenorhabditis elegans, development of the vulva begins when the _____ cell secretes _____, which then bind(s) to _____ on a(n) _____ cell.

Accepted Answer

A) progenitor; EGF; the EGF receptor; anchor 
B) progenitor; transcription factors; cis-regulatory regions; anchor 
C) anchor; EGF; the EGF receptor; progenitor 
D) anchor; transcription factors; cis-regulatory regions; progenitor 
E) type 1; EGF; the EGF receptor; type 2 
A) progenitor; EGF; the EGF receptor; anchor 
B) progenitor; transcription factors; cis-regulatory regions; anchor 
C) anchor; EGF; the EGF receptor; progenitor 
D) anchor; transcription factors; cis-regulatory regions; progenitor 
E) type 1; EGF; the EGF receptor; type 2

Question 4

If a Drosophila larva is missing much of its posterior end it is likely due to a mutation in the _____ gene.

Accepted Answer

A) maternal bicoid 
B) zygotic bicoid 
C) maternal nanos 
D) zygotic nanos 
A) maternal bicoid 
B) zygotic bicoid 
C) maternal nanos 
D) zygotic nanos

Question 5

Which of the following CORRECTLY lists the stages of human development in order?

Accepted Answer

A) fertilized egg, blastocyst, gastrula, morula 
B) fertilized egg, blastocyst, morula, gastrula 
C) fertilized egg, morula, blastocyst, gastrula 
D) fertilized egg, morula, gastrula, blastocyst 
E) fertilized egg, gastrula, morula, blastocyst 
A) fertilized egg, blastocyst, gastrula, morula 
B) fertilized egg, blastocyst, morula, gastrula 
C) fertilized egg, morula, blastocyst, gastrula 
D) fertilized egg, morula, gastrula, blastocyst 
E) fertilized egg, gastrula, morula, blastocyst

Question 6

Master regulatory genes that turn on entire programs of development are often identified because loss-of-function mutations and gain-of-function mutations in the gene have opposite phenotypes. Which type of mutation is recessive? Which type of mutation is dominant?

Accepted Answer

A) Loss-of-function mutations and gain-of-function mutations are recessive. 
B) Loss-of-function mutations are recessive; gain-of-function mutations are dominant. 
C) Loss-of-function mutations are dominant; gain-of-function mutations are recessive. 
D) Loss-of-function mutations and gain-of-function mutations are dominant. 
E) There is no predictable pattern of recessiveness or dominance. 
A) Loss-of-function mutations and gain-of-function mutations are recessive. 
B) Loss-of-function mutations are recessive; gain-of-function mutations are dominant. 
C) Loss-of-function mutations are dominant; gain-of-function mutations are recessive. 
D) Loss-of-function mutations and gain-of-function mutations are dominant. 
E) There is no predictable pattern of recessiveness or dominance.

Question 7

Pax6 is a transcription factor that can act as a repressor for some of its target genes or as an activator for others.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following graphs illustrates the pattern of Krüppel expression in a Drosophila embryo with a loss-of-function mutation in the zygotic hunchback gene?

Accepted Answer

A) graph A 
B) graph B 
C) graph C 
A) graph A 
B) graph B 
C) graph C

Question 9

What is present in cis-regulatory elements that makes their adjacent genes respond to developmental signals?

Accepted Answer

A) operator sequences 
B) CRP-cAMP binding sites 
C) binding sites for transcriptional activator proteins 
D) binding sites for transcriptional repressor proteins 
E) All of these choices are correct. 
A) operator sequences 
B) CRP-cAMP binding sites 
C) binding sites for transcriptional activator proteins 
D) binding sites for transcriptional repressor proteins 
E) All of these choices are correct.

Question 10

Which of the following graphs illustrates the relationship between Hunchback activity and Krüppel expression in the Drosophila embryo?

Accepted Answer

A) graph A 
B) graph B 
C) graph C 
D) graph D 
A) graph A 
B) graph B 
C) graph C 
D) graph D

Question 11

Review Figure 20.19. Which floral organ develops from whorl 1 in Arabidopsis?

Accepted Answer

A) sepal 
B) carpel 
C) petal 
D) stamen 
A) sepal 
B) carpel 
C) petal 
D) stamen

Question 12

Mutations in the Pax6 gene cause developmental defects in the eyes of flies, mice, and humans. This suggests that:

Accepted Answer

A) the eyes of flies, mice, and humans evolved by convergent evolution. 
B) Pax6 may be a master regulator of eye development. 
C) Pax6 has been evolutionarily conserved. 
D) Pax6 may be a master regulator of eye development that has been evolutionarily conserved. 
E) Pax6 may be a master regulator of eye development that has evolved independently in the lineages leading to flies, mice, and humans. 
A) the eyes of flies, mice, and humans evolved by convergent evolution. 
B) Pax6 may be a master regulator of eye development. 
C) Pax6 has been evolutionarily conserved. 
D) Pax6 may be a master regulator of eye development that has been evolutionarily conserved. 
E) Pax6 may be a master regulator of eye development that has evolved independently in the lineages leading to flies, mice, and humans.

Question 13

Early development in Drosophila includes nuclear division, but not cell division. This gives rise to a single cell with many nuclei.

Accepted Answer

A) True 
 B)False

Question 14

The progenitor cell that is closest to the anchor cell:

Accepted Answer

A) receives the largest dose of EGF. 
B) activates genes for differentiation into a type 1 cell. 
C) prevents the adjacent cells from differentiating into a type 1 cell. 
D) induces the adjacent cells to differentiate into type 2 cells. 
E) All of these choices are correct. 
A) receives the largest dose of EGF. 
B) activates genes for differentiation into a type 1 cell. 
C) prevents the adjacent cells from differentiating into a type 1 cell. 
D) induces the adjacent cells to differentiate into type 2 cells. 
E) All of these choices are correct.

Question 15

Review Figure 20.19. Which floral organ develops from whorl 2 in Arabidopsis?

Accepted Answer

A) sepal 
B) carpel 
C) petal 
D) stamen 
A) sepal 
B) carpel 
C) petal 
D) stamen

Question 16

Consider a gene affected by two transcription factors, U and V. Transcription of the gene takes place in the presence of U alone or of V alone, but when U and V are present together transcription is repressed. This is an example of:

Accepted Answer

A) epigenetic control. 
B) hierarchical control. 
C) chromatin remodeling. 
D) combinatorial control. 
A) epigenetic control. 
B) hierarchical control. 
C) chromatin remodeling. 
D) combinatorial control.

Question 17

A model organism called Caenorhabditis elegans (a soil nematode) has been used to study cell signaling during development because of its simplicity. For example, a structure such as the vulva arises from only three cells, which are called _____ cells.

Accepted Answer

A) progenitor 
B) anchor 
C) egg 
D) notch 
E) tail 
A) progenitor 
B) anchor 
C) egg 
D) notch 
E) tail

Question 18

In a Drosophila oocyte, bicoid mRNA produced by the mother is localized at one end of the egg rather than evenly distributed throughout the egg. This is an example of:

Accepted Answer

A) translational control of gene expression during development. 
B) translational control of development. 
C) hierarchical control of gene regulation during development. 
D) maternal developmental effect. 
E) oocyte polarization. 
A) translational control of gene expression during development. 
B) translational control of development. 
C) hierarchical control of gene regulation during development. 
D) maternal developmental effect. 
E) oocyte polarization.

Question 19

The rate of transcription for any one gene in any given cell type is determined by only one transcription factor.

Accepted Answer

A) True 
 B)False

Question 20

During the development of the vulva in Caenorhabditis elegans, when the Notch ligand binds a Notch receptor on a progenitor cell:

Accepted Answer

A) signal transduction results in activation of a set of transcription factors. 
B) genes that produce the Notch ligand are transcribed. 
C) genes that produce the Notch receptor are inhibited. 
D) genes that produce the EGF receptor are inhibited. 
E) None of the answer options is correct. 
A) signal transduction results in activation of a set of transcription factors. 
B) genes that produce the Notch ligand are transcribed. 
C) genes that produce the Notch receptor are inhibited. 
D) genes that produce the EGF receptor are inhibited. 
E) None of the answer options is correct.

Exam 20: Genes and Development

Which one of the following statements about Pax6 and eye development is INCORRECT?

In animals, homeotic genes:

In the roundworm Caenorhabditis elegans, development of the vulva begins when the _____ cell secretes _____, which then bind(s) to _____ on a(n) _____ cell.

If a Drosophila larva is missing much of its posterior end it is likely due to a mutation in the _____ gene.

Which of the following CORRECTLY lists the stages of human development in order?

Master regulatory genes that turn on entire programs of development are often identified because loss-of-function mutations and gain-of-function mutations in the gene have opposite phenotypes. Which type of mutation is recessive? Which type of mutation is dominant?

Pax6 is a transcription factor that can act as a repressor for some of its target genes or as an activator for others.

Which of the following graphs illustrates the pattern of Krüppel expression in a Drosophila embryo with a loss-of-function mutation in the zygotic hunchback gene?

What is present in cis-regulatory elements that makes their adjacent genes respond to developmental signals?

Which of the following graphs illustrates the relationship between Hunchback activity and Krüppel expression in the Drosophila embryo?

Review Figure 20.19. Which floral organ develops from whorl 1 in Arabidopsis?

Mutations in the Pax6 gene cause developmental defects in the eyes of flies, mice, and humans. This suggests that:

Early development in Drosophila includes nuclear division, but not cell division. This gives rise to a single cell with many nuclei.

The progenitor cell that is closest to the anchor cell:

Review Figure 20.19. Which floral organ develops from whorl 2 in Arabidopsis?

Consider a gene affected by two transcription factors, U and V. Transcription of the gene takes place in the presence of U alone or of V alone, but when U and V are present together transcription is repressed. This is an example of:

A model organism called Caenorhabditis elegans (a soil nematode) has been used to study cell signaling during development because of its simplicity. For example, a structure such as the vulva arises from only three cells, which are called _____ cells.

In a Drosophila oocyte, bicoid mRNA produced by the mother is localized at one end of the egg rather than evenly distributed throughout the egg. This is an example of:

The rate of transcription for any one gene in any given cell type is determined by only one transcription factor.

During the development of the vulva in Caenorhabditis elegans, when the Notch ligand binds a Notch receptor on a progenitor cell:

Life: Chemical, Cellular, and Evolutionary Foundations

The Molecules of Life

Nucleic Acids and Transcription

Translation and Protein Structure

Organizing Principles: Lipids, Membranes, and Cell Compartments

Making Life Work: Capturing and Using Energy

Cellular Respiration: Harvesting Energy From Carbohydrates and Other Fuel Molecules

Photosynthesis: Using Sunlight to Build Carbohydrates

Cell Signaling

Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Cell Division: Variations, Regulation, and Cancer

Dna Replication and Manipulation

Genomes

Mutation and Dna Repair

Genetic Variation

Mendelian Inheritance

Inheritance of Sex Chromosomes, Linked Genes, and Organelles

The Genetic and Environmental Basis of Complex Traits

Genetic and Epigenetic Regulation

Evolution: How Genotypes and Phenotypes Change Over Time

Species and Speciation

Evolutionary Patterns: Phylogeny and Fossils

Human Origins and Evolution

Cycling Carbon

Bacteria and Archaea

Eukaryotic Cells: Origins and Diversity

Being Multicellular

Plant Structure and Function: Moving Photosynthesis Onto Land

Plant Reproduction: Finding Mates and Dispersing Young

Plant Growth and Development

Plant Defense: Keeping the World Green

Plant Diversity

Fungi: Structure, Function, and Diversity

Animal Nervous Systems

Animal Sensory Systems and Brain Function

Animal Movement: Muscles and Skeletons

Animal Endocrine Systems

Animal Cardiovascular and Respiratory Systems

Animal Metabolism, Nutrition, and Digestion

Animal Renal Systems: Water and Waste

Animal Reproduction and Development

Animal Immune Systems

Animal Diversity

Animal Behavior

Population Ecology

Species Interactions, Communities, and Ecosystems

Biomes and Global Ecology

The Anthropocene: Humans As a Planetary Force

Filters

In the roundworm Caenorhabditis elegans, development of the vulva begins when the ___ cell secretes _, which then bind(s) to _ on a(n) ___ cell.